Switching device



Sept- 24, 1957 E. s. LESLIE 2,807,692

SWITCHING DEVICE Filed Nov. 18, 1955 INVENTOR. .EDIVARD JJBJ'LEATYUKJVEX illnited States Patent f.

SWITCHING DEVICE Edward S. Leslie, Van Nuys, Calif., assignor to Radio IThis invention relates to switching devices, and particularly to athree-position switch having a positive off, or neutral, positionintermediate its two on positions.

In electrical circuits, particularly those which control theenergization of motors for driving a load in forward and reversedirections, switches, such as the toggle type, are frequently used. Inthese motor systems, sudden reverse energizations of the driving motorcan cause damage to the load driven thereby. This is particularly truewhen the motors drive film transport mechanisms in recorders,reproducers, and similar apparatus.

The present invention may be an integral part of, or an adjunct to, astandard toggle switch which prevents a sudden change in a circuit, suchas a motor energization circuit. The switch is suitable in places wherespace is limited. With the switch in one energization position, itcannot be thrown to its second energizing position without rotation ofthe switch handle 180 degrees. This prevents the sudden or rapidreversing of the circuits by providing a safety delay action between thetwo energizing positions.

The principal object of the invention, therefore, is to provide animproved switching device which prevents a sudden or rapid reversal ofelectrical circuits.

Another object of the invention is to provide an improved three-positionswitch which prevents the rapid actuation thereof between two energizingpositions.

A further object of the invention is to provide a switch knob or controlelement for a toggle switch which prevents the toggle switch from beingrapidly actuated between its two energizing positions.

The novel features which are believed to be characteristic of thisinvention, both as to the manner of its organization and the mode of itsoperation, will be better understood from the following description whenread in conjunction with the accompanying drawings, in which:

Fig. l is a side view, partially in cross-section, of a switching deviceembodying the invention, the device being shown in one on position;

Fig. 2 is a view similar to Fig. 1 showing the switch in its 0 orneutral, position;

Fig. 3 is a view similar to Figs. 1 and 2 showing the switch in a secondon position;

. Fig. 4 is a cross-sectional end view taken along the line 4-4 of Fig.2;

Fig. 5 is a cross-sectional view taken along the line 55 of Fig. 4; and

Figs. 6 and 7 are end views of the switch knob when the switch is in itstwo on positions.

Referring, now, to the drawings in which the same reference numeralsidentify like elements, a standard type of toggle switch 5 is shownmounted on a panel 6 by a threaded stud 7 and a nut 8. The switch hasthe usual type of tapered actuating lever9 which will reverse theelectrical circuits connected to the switch 5 over conductors 10.

On the lever 9 is mounted a T-shaped knob, shown 2,807,692 PatentedSept. 24, 1957 generally at 11, and having a substantially cylindricalbody portion 13 and a larger diameter cylindrical portion 14. Theportion 14 has a 180 degree face portion 15 thereof at an angle to theaxis of the body portion 13. The body portion has flattened sides 16 and17 diametrically opposite one another to facilitate the hand actuationof the knob.

The body portion '13 has a cylindrical recess 19 therein within which isa split sleeve 20 internally tapered to accommodate the lever 9. Thesleeve 20 has a cross end portion 21 with a tapered face to correspondwith the face 15. The sleeve 20 is held in position on the lever 9 by apair of set screws 23 and 24, as shown in Fig. 5. The sleeve 20 is splitat 25, as shown in Fig. 4, to permit the assembling thereof on the lever9. There is sufficient friction between the sleeve 20 and the lever 99to prevent the accidental rotation of the knob on the lever, but whichpermits the rotation of the knob when turned manually.

With the above construction, it is necessary that the switch be rotated180 degrees before it can be actuated between the position shown in Fig.1 and the position shown in Fig. 3. For instance, when the lever 9 isthrown from its on position in Fig. l to its 0 position, such as shownin Fig. 2, the side of the portion 14 perpendicular to the axis of theknob comes in contact with the adjacent surface of the panel 6,preventing further movement of the lever 9. Now, to throw the lever 9 toits other on position, the knob 11 must be rotated 180 degrees, asshownin Fig. 3, which permits the lever 9 to be moved to its other onposition. Thus, a standard toggle switch is provided with a safety knobwhich prevents the sudden actuation thereof between its two onpositions, the delay required preventing damage to reversible equipment.The safety knob occupies very little additional space to that requiredby the standard switch so that it may be used on panels where minimumspace is available.

I claim:

1. A switching device comprising a panel, a switch mechanism on saidpanel and adapted to be thrown to two different on positions and to anintermediate off position, said mechanism including an actuating lever,said lever having its axis perpendicular to said panel when in said offposition and at an angle to said panel when in said on positions, a knobmounted on said lever and having a portion of one endsurface of saidknob perpendicular to the axis of said lever and knob, and anotherportion of said end surface of said hub diametrically opposite saidperpendicular surface at an angle less than degrees to said axis, andmeans for attaching said knob to and for rotation on said lever.

2. A switching device in accordance with claim 1 in which saidlast-mentioned means includes a split sleeve adapted to surround saidlever and occupy a recess in said knob.

3. A switching device comprising a panel, a switch mechanism on saidpanel and adapted to be thrown to two different on positions and to anintermediate 01f position, said mechanism including an actuating lever,said lever having its axis perpendicular to said panel when in said oh?position and at an angle to said panel when in said on positions, a knobmounted on said lever and having a portion of one end surface thereofperpendicular to the axis of said lever, and another portion of said endsurface diametrically opposite said perpendicular surface at an angleless than 90 degrees to said axis, means for attaching said knob to andfor rotation on said lever, said last-mentioned means including a splitsleeve adapted to surround said lever and occupy a recess in said knob,said sleeve has an end surface at the same angle having the 3 anglesurface of said knob, said angle permitting said lever to be actuated toeither of its on positions when said angle surfaces are in certainpositions.

4. A switch actuating knob unit for a switch lever comprising anelongated body portion of a certain size and 'an end portion extendingat right angles away from said body portion, said portions having aeylindrical opening extending from one end thereof, said opening beingadapted to accommodate said lever, said end portion having a portion ofits end surface perpendicular to the axis of said knob unit and saidlever and another portion of said end surface at an angle less than 90degrees to said axis.

5. A switch actuating knob unit in accordance with claim 4 in which asleeve is provided between said lever and the inner surface of saidopening to hold said knob unit on said lever and permit rotation of saidknob unit on said lever.

References Cited in the file of this patent UNITED STATES PATENTS2,385,304 Schyrnik Sept. 18, 1945

